UHMW-PE plastic, a very tough and resilient industrial plastic. Similar to cutting boards.

Are your wheels susceptible to fire

A little! But you'll need tons of fire to heat them up to the point where they would melt or burn.

How tall is it?

40 inches tall.

Why didn't you put any grippy material on the wheels?

It's heavy! We showed up overweight by about 6 pounds without any rubber on, and have used rubberless tires before on smaller versions of HUGE without many problems. So we figured we'd just go with it!

Even if it couldn't burn hot enough to reach the melting point, steel (and UHMW-PE) soften at temperatures well below their melting point.

Either way, the wheels are very, very bendy (by design) in the direction axial to the disc, and while they may have been slightly softened by the heat, they would have bent almost as much without the heat.

This is correct. Yes the heat can affect them. No, we don't believe the heat affected them. UHMW grabs and holds onto heat very well, it doesn't cool quickly. Machining a part with the wrong speeds and feeds can deform the entire part, to the point where dimensions no longer match up once the part has cooled. I had a lot of learning to do, as the 3lb and 30lb Huges are almost entirely constructed from this plastic. The wheels were cool to the touch upon entering the arena, and even some hot glue in the support leg was untouched. Very sooty though!

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